Now, Teavana has shot back at firm, Glaucus Research Group, a short-seller that admits that it's biased.

"We are short Teavana and therefore stand to realize significant gains in the event that the price of stock declines," notes the Glaucus report. "We do not express any opinion as to whether any of the food products discussed herein are safe for human consumption."

Here's the full response from Teavana:

Teavana’s teas undergo rigorous third-party testing on each batch of teas based on international food safety standards including European Union regulations, which are widely considered to be the most stringent in the world.

Consistent with that, the Company has established internal procedures and comprehensive third party testing to ensure all tea is safe and within those guidelines.

Teavana refutes the report’s conclusions. The group that published the report is a short-seller and may benefit financially from the allegations in the report.

Teavana’s teas are safe and of the highest quality.

And here are the detailed claims from the Glaucus report:

a. Pesticides Abound. 100% of the tea samples contained pesticides, many of which are classified by the EPA as Possible Human Carcinogens. One of Teavana’s most popular and expensive teas, Monkey Picked Oolong, was the most contaminated with 23 pesticides.

b. Teas Violate US Law. 100% of the tea samples violate U.S. food pesticide standards (CFR Title 40 sect 180), meaning they are ‘adulterated’ under the FDCA and subject to federal seizure. We believe Teavana will recall its adulterated teas rather than risk the civil and criminal liability it may incur by knowingly selling adulterated products over Black Friday weekend.

c. Broad Failure of EU Pesticide Tests. Contrary to Teavana's representations in its SEC filings, 77% of the tea samples failed the European Union pesticide import standards (EC 396/2005) for dry teas, meaning that such teas would be banned from sale to consumers in the European Union.

d. Banned Pesticides. 62% of teas tested showed traces of the pesticide Endosulfan, which has been banned by the US, China, the EU and 144 other countries because its use may impair fertility, cause harm to unborn children and other damage to agricultural workers.